What is the value at the top of c++ stack S after the following operations?

What is the value at the top of the stack S after the given operations?

A. 7

B. 5

C. 4

D. 6

The value at the top of the C++ stack S

The value at the top of the C++ stack S after the given operations would be 4.

In the given sequence of operations, the initial stack is empty. The operations performed are as follows: S.push(5), S.push(4), S.push(6), S.pop(), S.push(7), and S.pop(). Let's go through these operations step by step.

First, S.push(5) adds the value 5 to the top of the stack, making the stack [5].

Then, S.push(4) adds the value 4 to the top of the stack, resulting in [5, 4].

Next, S.push(6) adds the value 6 to the top of the stack, giving us [5, 4, 6].

The operation S.pop() removes the topmost element from the stack, which is 6. After this, the stack becomes [5, 4].

After that, S.push(7) adds the value 7 to the top of the stack, resulting in [5, 4, 7].

Finally, the operation S.pop() removes the topmost element from the stack, which is 7. After this, the stack becomes [5, 4].

Therefore, the value at the top of the stack S is 4.